Escherichia coli is a rod-shaped bacteria that can be commonly found in the lower intestine of warm-blooded organisms. It is the primary facultative anaerobe of the human gastrointestinal tract. Most E. coli strains are harmless, but some serotypes can cause food poisoning and diseases in humans. Pathogenic strains of E. coli usually cause gastroenteritis, urinary tract infections and neonatal meningitis. There are various strains of E. coli which are producers of potentially lethal toxins, like for example E. coli O157:H7. Food poisoning caused by E. coli can be the result of consummation of unwashed vegetables or undercooked meat. In order to reduce food contamination with E. coli, scientists are trying to develop adequate methods that are capable of eliminating pathogenic microorganisms during food processing.